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The Use of Astacus leptodactylus (Eschscholtz, 1823) as a Test Species for Toxicity Evaluation of Municipal Wastewater Treatment Plant Effluents
2020
Cikcikoglu Yildirim, N. | Aksu, O. | Tatar, S. | Yildirim, N.
This study evaluated the responses of biochemical biomarkers in Astacus leptodactylus exposed to treated municipal effluents discharged into Keban Dam Lake, Elazığ Elazig, Turkey. A. leptodatyclus were exposed to treated municipal effluents and Catalase (CAT), Superoxide dismutase (SOD) activity and lipid peroxidation (TBARS), glutathione (GSH) levels were measured as oxidative stress biomarkers. SOD activity was increased after exposing to treated municipal effluents for 24th and 96th h. CAT activities were decreased from 25.29 to 14.12 nmol/min/ml compared to control in the group exposed to treated municipal effluents for 24 h but it increased after 96 h exposure. GSH levels were decreased from 9.08 to 3.77 µM compared to control, but MDA levels were increased both at 24 th h and 96 th h after exposure to treated municipal effluents. CAT, SOD activities and MDA and GSH levels in the hepatopancreas of A. leptodactylus are sensitive and suitable biochemical biomarkers for evaluating the toxicity of the treated municipal effluent complex mixtures. Treated municipal effluents exposure was found to cause sub-lethal responses in A. leptodactylus suggesting oxidative stress.
Mostrar más [+] Menos [-]Analysis of Heavy Metal Contents and Non-carcinogenic Health Risk Assessment through Consumption of Tilapia Fish (Oreochromis niloticus)
2020
Tayebi, L. | Sobhanardakani, S.
Due to the fish are often at the top of the aquatic food chain and may accumulate large amounts of heavy metals from the water, this study was conducted to determine of Cd, Cr, Pb and Ni contents in the muscle of imported tilapia fish marketed in the city of Hamedan in 2017. In so doing, totally, 27 muscle samples from nine different brands of tilapia fish were randomly collected from the market basket of the study area. After preparation and processing the samples in the laboratory, the concentration of metals, was determined using inductively coupled plasma-optical emission spectrometer. The results showed that the mean concentrations (mg/kg) of Cd, Cr, Pb, and Ni in samples were 0.26 ± 0.09, 1.54 ± 0.15, 0.55 ± 0.11, and 0.67 ± 0.20 respectively. Also, the mean contents of Cd and Pb were higher than the maximum permissible levels (MPL) established by the World Health Organization (WHO). The computed health risk index values showed that no potential health risk for adults and children via consuming the muscle of tilapia fish at the current consumption rate for the study area. Based on the results, due to the mean contents of Cd and Pb in the muscle samples of tilapia fish were higher than the MPL, therefore, serious attention to the reduction of the discharge of hazardous substances in the aquatic ecosystems and also periodic monitoring of chemical residue particularly toxic heavy metals in the high-demand food is recommended.
Mostrar más [+] Menos [-]O-Anisidine Degradation by Fenton’s Reagent and Reaction Time Estimation
2020
Chaturvedi, N. K. | Katoch, S. S.
O-Anisidines (OAs) are extensively used as an intermediate for chemical reactions to produce various triphenylmethane and azo dyes, and also in manufacturing numerous pigments. They are found to be highly toxic and have carcinogenic properties, so it is imperative to treat OA solutions before disposal. In this study a promising approach to degrade OA solutions has been carried out using Fenton’s reagent. Oxidation trials were conducted for 24 hours and various parameters – OA removal, pH, effect of H2O2 and Fe2+, and COD removal – were analysed to understand the oxidative degradation of OA. For varying initial OA concentrations, the OA and COD removal efficiencies of 72 to 85% and 62 to 74%, respectively, were obtained at pH = 3, and at different optimum H2O2 and Fe2+ doses. Lower initial concentrations of OA showed better removal efficiencies. The reaction time was estimated to 360 minutes after which there was negligible degradation occurs.
Mostrar más [+] Menos [-]Production of Nanofibers Containing Magnesium Oxide Nanoparticles for the Purpose of Bioaerosol Removal
2020
Dehghan, S. F. | Golbabaei, F. | Mousavi, T. | Mohammadi, H. | Kohneshahri, M. H. | Bakhtiari, R.
The present study aims at investigation of the performance of nanofibrous filter, containing magnesium oxide (MgO) nanoparticles, for bioaerosols removal from the air stream. It synthesizes two types of polyacrylonitrile (PAN) and PAN/MgO nanofibers via electrospinning technique, and investigates the antibacterial properties of the produced nanofibers through disk diffusion. The air containing staphylococcus epidermidis is introduced into the filter test rig by a nebulizer and air sampling from the microorganisms takes place before and after the filters by means of a cascade impactor with blood agar culture medium, with the filters, themselves, examined at two states of UVC radiation and dark. The mean diameters of PAN/MgO and PAN are 221.38±65.56 nm and 320.25±87.35 nm, respectively, with the mean length of the inhibition zone for these nanofibers calculated as 0 (for PAN) and 2.8 mm (for PAN/MgO). It turns out that the mean percentage of filtration efficiency is higher in case of PAN/MgO than PAN nanofiber filter; however, the former displays higher mean pressure drop than the latter. For both types of nanofibers under UVC radiation, the mean percentage efficiency for bioaerosol removal is higher than in the dark.
Mostrar más [+] Menos [-]Appraisal the Protective Effects of Cymbopogon Schoenanthus Extract against Reproductive Disorders and Carcinogenic Effects of Formalin in Experimental Male Rats
2020
Sief, M. M. | Sherif, S. M. | Abdel-Aziz, M. H. | Sherein, S. A. | Mona, M. A. | Ramzy, S.
Formaldehyde has been documented to be naturally present in many common foods. There has been a big public concern over the use of formaldehyde in the preservation of food. Also, it is commonly used as a chemical substance, usually in the life and can interact with many bio-substance in the human body. The present study target to investigate the protective effects of Cymbopogon schoenanthus (CS) extract against the reproductive and carcinogenic effects of formaldehyde on male rats. The Albino male rats were divided into equal six groups, first group: rendered as a control group; second group: received formalin (100 mg/kg bw) and third group and forth group: were received SC extract at (50 and 100 mg) respectively; fifth group and sixth group were received formalin (100mg /kg bw) + SC extract (50mg) and formalin (100mg /kg bw)+ SC extract (100 mg) respectively. At the end of the experiment the animals were scarified and blood samples were collected for measurement all tested parameters. The results showed that the oral exposure to formaldehyde at a dose of 100 mg/kg bw resulted in significant negative effects in all tested parameters, while the CS extract at tow doses (50 and 100 mg) alone or in combination with formalin restored the negative effects to normal levels compared with the untreated group. The histopathological examination was studied on testis tissues and the histopathological pictures showed the CS extract at tow mention doses had ameliorate the adverse effects that induced by formaldehyde hazards.
Mostrar más [+] Menos [-]The Effectiveness of the Ballast Water Exchange Method in Removal of the Heavy Metals in the Ballast Tanks of the Ships, Bushehr Port- Persian Gulf
2020
Tolian, R. | Javadzadeh, N. | Sanati, A. M. | Mohammadi Roozbahani, M. | Noorinejad, M.
Ships transport about 80 percent of world trade and transfer approximately three to five billion tons of ballast water internationally every year. Due to the likely presence of pollutants, the ballast water discharged by ships can have negative effects on aquatic ecosystems. This study was conducted on 10 ships that entered the Bushehr port to determine the effectiveness of the ballast water exchange method and also to specify the contents of heavy metals (Ni, Cd, Pb and Cu) in the water and sediment of the ships’ ballast tanks. The samples were collected from January 2017 to July 2018 during a cold and a hot season. The results indicate the values of heavy metals in the samples in this order: Ni> Cu > Pb > Cd. The heavy metals concentrations in the sediment samples did not exceed the standard of the National Oceanic and Atmospheric Administration (NOAA). Whereas, Cu and Ni in all water samples and Cd in samples 2 and 7 exceeded the NOAA quality standard value. A correlation analysis of the metals showed that the sources of heavy metals vary in water and sediment samples, except for Pb and Cu in sediment samples which a positively significant relationship were observed. The results also revealed that the ballast water exchange method cannot by itself be effective and an efficient management together with continuous monitoring seems to be essential to prevent pollution of the ballast tanks of the ships entering the Bushehr port.
Mostrar más [+] Menos [-]Chronological Studies of Traffic Pollution Using Elemental Analysis of Tree Rings: Case Study of Haatso-atomic Road
2020
Edusei, G. | Tandoh, J. B. | Edziah, R. | Gyampo, O.
Mitigation of atmospheric pollution has been a topic of concern over the past decades. In this study, tree rings have been used to reconstruct past climates as well as to assess the effects of recent climatic and environmental changes on tree growth. Vehicular emission is one of the major sources of pollutants in the atmosphere and this study focused on the Haatso-Atomic road which over the years has been a spot for heavy vehicular traffic. Swietenia mahagoni (Mahogany) tree was logged and the rings counted and age determined to be 61 years spanning from 1957 to 2018. X-ray fluorescence (XRF) was used to investigate the presence of the following heavy metals. Heavy metals (Cu, Mn, Zn, Pb, Cd and Ni) which ranged from (3.15—9.84mg/kg), (2.58 – 5.49 mg/kg), (8.18 – 15.78mg/kg), (0.12—0.60 mg/kg), (0.01—0.09 mg/kg) and (0.10 – 0.99 mg/kg) respectively, from vehicular emissions were determined for annual rings spanning from 1957 to 2018 and surprisingly an increasing trend was observed with some the heavy metals exceeding WHO guidelines. Tree growth rates were calculated through ring width measurements and related to annual precipitation data spanning over the sampling period. It was observed that wet seasons correlate with high growth rates of trees while low precipitations seasons related to low or no growth rate of trees.
Mostrar más [+] Menos [-]Using Benthic Diatoms as a Bioindicator to Assess Rural-urban River Conditions in Tropical Area: A Case Study in the Sai Gon River, Vietnam
2020
Pham, T. L.
The changes in diatom assemblages along an urban-to-rural gradient were characterized to assess the ecological status of the Sai Gon River, Vietnam. Diatoms and physico-chemical variables were measured at 10 stations during dry and rainy season. One-way ANOVA showed that diatom metrics and physicochemical variables were significantly different (p < 0.05) between the upper course sites and both the middle- and the lower sites. However, no significant differences were observed between the middle course sites and the lower course sites. Achnanthidium minutissimum and A. exigua were potential indicators of low nutrient in the upper course sites; Melosira granulata and Navicula viridula were preferred moderately eutrophic water in the middle course sites; while Navicula cryptocephala and Nitzschia palea were tolerant to very heavy pollution and dominant in the lower course sites. Canonical correlation analysis (CCA) results showed that concentration of TSS, TN, TP, BOD5 and COD were the most important factors in structuring benthic diatom communities in the Sai Gon River. The results of this study indicated that diatom community was sensitive to changes in urban condition and could be used as an indicator of urbanization.
Mostrar más [+] Menos [-]Fixed Bed Column Modeling of Cd(II) Adsorption on Bone Char Using Backward Bayesian Multiple Linear Regression
2020
Amiri, M. J. | Mahmoudi, M. R. | Khozaei, M.
In this work, the backward Bayesian multiple linear regression (BBMLR) as a new approach is presented to predict the adsorption efficiency (AE) of Cd(II) ions by ostrich bone char (OBC) in the fixed bed adsorption with four operational variables consisting of pH (2-9), inlet Cd(II) concentration (Co= 25-100 mg/L), bed depth (h= 3-9 cm) and feed flow rate (Q= 0.5-30 mL/min). The performance of the BBMLR was evaluated using the coefficient of determination (R2), normalized root means square error (NRMSE) and mean residual error (MRE). The AE of Cd(II) ions by OBC increased from 42.3% to 99.9% when pH was increased from 2 to 9 with h of 6 cm and Q of 1.5 mL min-1. It was found that the AE dramatically increased from 70.5% to 99.9% with decreasing Q from 30 to 0.5 mL min-1 at pH of 7 and h of 6 cm. At pH= 7 and Q= 1.5 mL min-1, the AE increased from 71.9% to 100% when h increased from 3 to 9 cm. The BBMLR model presented excellent performance (NRMSE=6.69%) for predicting Cd(II) removal in a continuous adsorption system, although it gave a slight underestimation (approximately 3.52%). The BBMLR is more sensitive to the pH, followed by h and Q, while the Co has no significant effect on it. This research displays that OBC has great potential as an eco-friendly low-cost adsorbent in removing Cd(II) ions from the contaminated waters.
Mostrar más [+] Menos [-]Diversity of Lichen Flora in Mt. Kitanglad Range Natural Park, Kaatuan, Lantapan, Bukidnon
2020
Cababan, M.L. | Memoracion, M. M. | Naive, M. A.
This study was conducted to identify and classify the lichens; determine the diversity index and richness of lichens. A total of 36 species belonging to six genera under three families was identified. Lichen species were mostly found at moderate high altitudinal range with an elevation of 1,131 meters above sea level and open areas where they received adequate sunlight with high moisture and humidity contents. Diversity, composition and altitudinal distribution of lichens was evaluated in Mt. Kitanglad Range, Kaatauan, Lantapan, Bukidnon, Philippines a wet forest type forest. The maximum species richness was reported on Usnea rubicunda Stirt. The abiotic factors were shown to be essential in adapting the relative abundance of lichens for it is capable to survive in the range of light levels, it appears that drier and lighter conditions competitively favored. Additionally, lichen diversity is dependent on the climatic and environmental conditions which makes them as an excellent biological indicators of ecosystem changes in the forests of Mindanao Island, Philippines.
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